Cyclists and sperm are topics that often feature together in the news. A couple of years ago the mainstream press reported keen male cyclists as being at risk of having a low sperm count. And aerial pictures of the peloton heading towards a bunch sprint can seem eerily reminiscent of those grainy films we watched in biology classes at school as millions of sperm competed in their own race. But nothing has prepared us for the arrival of the Sperm Bullitt bike, currently plying the streets of Copenhagen.

The rather arresting custom-made cargo bike belongs to the European Sperm Bank, and ferries samples of sperm between fertility clinics in the Danish capital in a special freezer compartment contained within the head of the giant sperm that is the bike’s most striking feature.

News of the bike’s appearance on the city’s streets was broken by Mikael Colville-Andersen on his Copenhagenize website, where more pictures are available. The bike itself is a Danish Bullitt produced by local company Larry vs Harry.

Quoted on Copenghagenize, Peter Bowers, CEO of the European Sperm Bank, says: "The first idea was how we could deliver to the fertility clinics in a C02-friendly way. Shortly afterwards followed the idea of a custom-designed bike with a cooling system. Now, six months later, we can cycle around the city on our sperm cell bike."

He adds: "We're always looking for new donors so it's a fine bonus that the Sperm Cell Bike gets people’s attention."

That we don’t doubt. It certainly grabbed us by both balls (should have seen that one, er, coming – ed).